Refractory resistor-supporting plate



Patented Mar. 12, 1929.

FREDERICK E. OWEN, OF EAST PALESTINE, OHO.

REFRACTORY RESISTOR-SUPPORTING PLATE.

Application filed November 4, 1927.

My invention relates to electric heating units and particularly to refractory resistor- ,supporting plates therefor.

An object of my invention is to provide a relatively simple, compact, and inexpensive resistorsupporting plate.

Another object of my invention is to provide a refractory 1;'esistorsu1' porting and heat-insulating plate embodied in a unitary structure.

ln practicing my invent-ion, I provide a tired refractory ceramic resistor-supporting plate of substantially standard design and construction, ha Jving closely adherent to ene of its surfaces, a relatively thick layer of heatinsulatingl material that has been air-dried in its proper operative position relatively to the fired plate.

The desirability or necessity for providing a layer of heat-insulating material below a refractory heater brick has long been recognized and it has heretofore been customary to make the two members entirely separate from one another. This means that the relatively brittle heat-insulting plate must be manufactured and handled separately, with the result that too large a percentage thereof are chipped or broken in shipment or in assembly. The device embodying my invention provides,'as noted above, a unitary assembly embodying both parts.

In the single sheet of drawings,

Figure 1 a view, in vertical section, of a unitary heater brick embodying my inven- :;5 tion,

g. 2 is a view, in vertical section, of a device embodying my invention. shown duri ng its process of manufacture,

Fig. 3 is a bottom plan view, with portions broken away, of a modified form of device embodying my invention, and

Fig. l is a View, in lateral section therethrough, taken on the line IV-IV of Fig. 3.

A refractory ceramic heater brick 11 is shown in vertical section in Figs. 1 and 2 of the drawings and may be of any desired size, shape, and contour. I have shown a substantially circular brick, which is provided, in one face thereof with a spiral groove no 12 having walls 13 located between adjacent grooves. A helically-wound resistor wire 1a is located within the groove 12. Bridges 15 extend across the groove 12 at spaced intervals in order to retain the resistor wire 14, within the otherwise open groove 12.`

Openings 1G extend through the body por- Serial No. 23 1,000.

tion of the plate 11 beneath the bridge 15,

these openings being made necessary by the use of rods provided. in the molds in order to p ermi I of molding the bridges 15 at the saine time that the body portion of the heater bric of course, well known in the art. eric thc usual manner.

s being molded. The use of these rods This k is molded, air-dried, and then tired in central opening 17 is also provided to permit the inner end of the resistor wire 14 to extend downwardly through the body portion of the plate 11. The other end of the resistor wire extends downwardly through a suitable opening near the periphery of the plate. this opening not being shown in the draw .g A relatively heavy plate or layer 18 of refractpry 1lieat-insulating material is located closely adjacent and cemented to the bottom Jce of the plate 11. Integral portions of able bench or other plane surface 21.

and a clamping ring 22 :is placed therearouml titting t ,c illy the Any suitable device may be employed ci'lcctire for the purpose desired, namely to provide a peripheral wall for a plastic mass of the above mentioned heat-insulating mixture. The central opening 17 is filled with a rod 23.

The openings 1G are filled with small masses 19 of the mixture of kieselguhr and plaster Paris, the consistency of which is such that an operator can place the quant-ities 19 in the openings 1G to close them.

The moi stened mixture is then poured into the mold thus provided and is allowed to dry in the open air until thoroughly dry. I have found that a layer 18 thus made adheres closely to the adjacent surface of the heater brick by its own cementing action and is held also by the small masses 19 located within the openings in the fired heater brick.

Figs. 3 and lshow a modified form of structure embodying my invention.

A refractory ceramic bricl 3l or plate form embodies a groove 32 for receiving a resistor therein. Bridges Se integral with the Walls 35 of the grooves are provided, all as hereinbeiore set orth in connection with the device shown in l and 2. The brick er plate 31 embodies also an integral peripheral depending flange portion 35 and a plurality ot radially-extending integral bottom ribs 37, an integral central hub portion 38 being? also provided.

A mass 39 of a mixture ot iniinsorial earth and plaster Paris, as hereinbefore describef, is located in each of the sections defined by a part of the cepending` iiange 36 portion and tivo adiacent radial ribs Small masses el, oi" the saine mixture, are pressed into the openings l2 ander the bridges Se, all has hereinbeiore been described. The masses 39 of the mixture of infnsorial earth and plaster l)aris will adhere closely to the bottoni snr- 'aee of the brick 3l and to the small masses ll by their inherent cemcnting action. The masses 39 are air-dried as Was liereinbefore described.

The amount of the mixture of ini'usorial earth and plaster is just sutlicient to lill the recess, the bottom surface of 'the masses being even with the bottom edge el: the iiangge 36 and of the ribs 37. The briclrmay be located in an inverted position on a suitable table or support d :ring this operation. The heat-insulating material interi'its with the tired ceramic brick` constitiltingv a unitary assembly in which one mass oi material supports the other.

A unitary structure of this lrind is relan tively inexpensive and Will withstand a relatively large amount ci handling` during,` shipment and assembly Without serions danger or cracking or breaking off of the heat-insulating material Which has been cemented against the refractory ceramic brick.

The device embodying my invention thus provides a relativelyv simple, compact, and

effective unitary structure embodying a 'tired refractory Ceramic resistor-supporting plate an d a. layer or refractory heat-insulating` inaterial located closely adjacent `and adherent to one surface of the fired plate, the heat-insulating` material being` air-dried only.

Various modifications may be made in the device einbodying` my inrention and l desire that only sneh limitations shall be placed thereon as are imposed y the prior art or are set o'rth in the appended claims.

l claim as my invention :u

l. As a nen7 article et' manufact* re ot' the class described, unitary selsnpporting assembly consistin of ceramic resistorwnpporting' plate and a layer of heat-insulating material located against one s rface only therefor l inherently cemented tliereagainst.

2. ris a new ar le or' manufacture of the class described, a unitary assembly comprising a ceramic re istor-snpporting plate, and a layer of heat-ins datinej material comprising infnsoriai earti a :l plaster Paris n herently cemented one surface of the refractory plate. y

As a new article of manufacture of the escribed, a nmtarjv assembly compriseran'iic resist-or-siipiiorting plate, hav- -f singsthereiirongli, and a layer of sulating aaterial located against and I to one surface o1 the nd having por ions thereof extcneing into the openings in said plate.

e. As new article of manufacture of the a ired plate oit refractory material and a Yer of a mixture of a comminnted heat-inatinsoY material and a binder of plaster raris molded into intimate Contact with one opposite to its heating surface andv CII 

